Calling dial device



Jan. 1954 w. G. BREIVOGEL CALLING DIAL DEVICE 2 Sheets-Sheet 1 Filed Dec. '7, 1950 //v VENTOR W W. G. BRE/I OGEL ATTORNEY Jan. 12, 1954 w. G. BREIVOGEL 2,666,097

CALLING DIAL DEVICE Filed Dec. 7, 1950 2 Sheets-Sheet 2 llVl/E/W'OR BY n G. B/PE/VOGEL ATTORNEY Patented Jan. 12, 1954 CALLING DIAL DEVICE William G. Breivogel, Summit, N. J., assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New York Application December '7, 1950, Serial No. 199,608

3 Claims. I 1

This invention relates to telephone calling dials of the rotatable finger wheel type and more particularly to a mounting for removably securing the finger wheel to the operating shaft of the dial.

One object of this invention is the provision of a simple one-piece mounting for molded finger wheels which while readily permitting the assembly and disassembly of the finger wheel by an authorized person is substantially tamper-proof by an unauthorized person.

Another object of the invention is the provision of a finger wheel mounting which comprises a comparatively small number of parts, is efficient in operation and is economic to manufacture.

In the assembly and disassembly of finger wheels of calling dials, and particularly those constructed of plastic or similar molded material, it has been found that the mounting and method of securing metal finger wheels to the dial operating shaft is not practical, since the indicia holder is integral with the molded finger wheel and not a separate item as in the well-known metal type of finger wheel. It is with the securing of the molded type finger wheel to the operating shaft of the dial in a simple, efficient, tamper-proof inexpensive way that this invention is concerned.

In one preferred embodiment of my invention, I provide a fiat substantially triangular shaped member which is adapted to be secured to the extending end portion of the dial operating shaft. The extremities of the triangular member are provided with lobes or ears which are adapted to engage circumferential slots or recesses in the inner wall of the indicia holder, upon the rotation of the finger wheel counterclockwise, to position the finger wheel on the triangular member. An extending spring member, integral with the triangular plate, engages a vertical slot on the inner wall of the indicia holder to lock the finger wheel in place. An aperture communicating with the vertical slot permits a tool to be inserted therein to engage and release the spring, thereby permitting the ready removal of the dial by rotating it in a clockwise direction.

The invention will be more clearly understood from the following detailed description when read in conjunction with the following drawings in which:

Fig. 1 is a side elevational view, partly in sec-- tion, of a calling dial embodying the invention;

Fig. 2 is an exploded perspective view of the calling dial shown in Fig. 1, with the finger wheel removed from its mounting;

Fig. 3 is a fragmentary perspective view of the underside of the indicia holder, with the mounting plate positioned therein, in its unlocked position;

Fig. 4 is a view similar to Fig. 3 but shows the mounting plate in its locked position;

Fig. 5 is a fragmentary view, in section, showing the locking spring in its locked position; and

Fig. 6 is a view similar to Fig. 5 but shows the locking spring pushed out of its locked position by means of a suitable tool.

The calling dial as shown in Figs. 1 and 2 comprises a casing Iii and a finger wheel II, and a number plate I2. The finger wheel II is constructed of plastic or some similar molded material, is located above and in spaced relation with respect to the number plate I2 and is secured to and supported on the shaft I3 by means of the mounting plate member M. The mounting plate [4 is provided with a rectangular aperture which engages a flattened portion on the shaft I3 to prevent movement therebetween and is held in place by means of the nut I5. The shaft I3 extends downwardly through the number plate I2 and into the casing Ill and is intended to be operated by the manual rotation of the finger wheel II in the wind-up stage, to store energy in the drive spring (not shown). Release of the finger wheel I I will cause the shaft I3 to rotate and cause the operation of the arm I6 and the contacts I! and I8 associated therewith to send out signal impulses over the line to obtain the desired connection.

As shown in the drawings, the mounting plate I4 is substantially in the shape of an equilateral triangle and is provided on its extremities with lobes or ears I9, 20 and 2|, which have an arcuate profile. As heretofore described, the mounting plate I l is fitted over the shaft I3 and secured thereto by means of the nut I5 which forces the plate down into engagement with a shoulder on the shaft 53, which maintains said plate in juxta-' position with respect to the number plate I2. and locked in position by means of the embossings r EB.

The finger wheel II as shown in the various figures, and more in detail in Figs. 1 and 2, is provided with an integral indicia holder, which comprises a central circular aperture 22 having an inturned rim or flange 23 which confines and acts as a frame for the indicia members 24 and 25 and the spring backing plate 26. The inner wall of the indicia holder as shown in Figs. 2, 3, and 4 is provided with spaced recesses 21, 28 and 29 which communicate with circumferential grooves 30 on the inner wall 31 of the central aperture 22 and which are adapted to receive the lobes I9, 20 and 2| on the plate member I4. A spring member 32 is formed integral with mounting plate l4 and has its end 33 extending slightly beyond the ends of the lobes I9, 20 and 21 and is slightly off-set with respect to the plane of the plate l4., Asshown in Figs. 3 to 6,-inclusive, the end 33 of" the spring 32, is adapted to engage a tapered recess 34, on the inner wall SI of the aperture and be positioned in the vertical aperture 35 which passes through flange 23. at point.

locked position, with the lobes i9; 29 and El in register with the recesses 27,28 and 29,,and with.

the end 33 of the spring 32, in engagement with the tapered portion of the recess 34. Thefigure.

shows in dot and dash lines the position assumed bYi'thQlOb6S ltgfid andZ land thejend 33 of spring 32,;w-hen, the, finger wheel 12 is rotated in a counterclockwise direction to cause the lobes to enter the circumferential grooves 33 and the end ofithespring to'enter the recess 35.

As shown in Fig. i, the finger wheel i i has been rotated counterclockwise-until the end 33 of the spring32registers with and locks itself in position in the :recess 3.5, with the lobes i9, 20. and 2i in: position in the grooves 39], thereby firmly securing the finger wheel H to the shaft l3 through the medium of the mounting plate it.

.In practicing the invention herein described, the first step ,inthe application of the finger wheel toitssupport is-tosecuregthe mounting plate M to' the shaft. l3, sothat the end 33 of the spring 32. is opposite theletter X on the number plate l2, by: meansqoi the nut Iii. The next step is to position the finger wheel I! over the mounting plate 14, sothat therecessesfl, 28 and29, register with the lobes; it, as, andZl, which is when the last fingerwheel hole HL isin alignment with the letters WXY on the number plate l2.

When-the finger wheel 5 I has been positioned, as, described, it .is rotated counterclockwise until the'end seer the spring 32 snaps into the recess 34'. and is positioned in the bottom thereof as shown in Fig. 5; thereby securely locking the finger wheel I i to the mounting plate It.

Asshown-in Fig. 6, when it is desired to remove thefinger wheel H,,a toolTLis inserted through the-apertureflfi' into the recess 35and into engagement with the end 33 of the spring 32. Down wardpressure on the tool causes the end 33 of the spring32 to become disengaged from the recess 34; Holding the end of the, spring 32 depressed,

as; shown, the finger Wheel H may be rotated.

cloekwisewhich causes theend 33 of thespring 32;,torideon the wall of the tapered recess 34 and permitsthelobes l9, 2t and 2! to slide in the While I have shown and described the preferred embodiment of my invention it is to be understood that various changes and modifications may be made therein without departing from the spirit of the invention.

What is claimed is: V

1. In a telephone calling device, a rotatable shaft, a finger wheel having, arecessgin one face thereof, said finger wheel having also at the periphery of said recess a plurality of spaced slots extending inwardly from said face, a plurality of circumferential grooves in communication with said slots and a tapered recess terminating in a stop opening, amounting member coupled to said shaft'and having lobes at its periphery insertable into said slots and upon relative rotation between said, finger wheel and plate, slidable into said grooves, said mounting member having integral therewith a resilient finger, and said finger having an end portion adapted to fit into said tapered recess and upon said'relative rotationtobe. guided thereby into said stop opening, thereby to; lock"v said finger wheel to said plate member.

2. In a telephonecalling device, the combination defined by claim 1 wherein said finger wheel. hastherein a restricted aperture extending from theopposite face thereof into said stop recess}. whereby said resilient fingermay be disengaged from said stop recess by insertion of atool-into; said restricted aperture.

3. In a telephone calling. device,.a rotatable. shaft, a finger wheel having a circular recess; in one face thereof, the peripheral wall of saidirecess; having therein spaced circumferential grooves. three spaced slots communicating with. said grooves and a tapered recess terminating in a" stop opening, a plate member having'a substan-- tially triangular body portion and lobes at the apices of said body portion adapted to fit injsaid. grooves, said slots being spaced in the same .relation as and wider than said lobes, whereby said.- plate member is insertable into said recess; and upon relative rotation of said finger wheel and; plate member said lobes slide into said grooves; said plate member having integral therewithiand: extendingfrom said body portion a substantially J shaped finger the outer end of which is; adapted; to, fit into said tapered recess and upon saidrelae tive rotation to be guided by said tapered recess into said stop opening.

WILLIAM G. BREIVOGEL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,194,306 Huxham Mar. 19, 1940 2,307,226 Lum Jan. 5, 19%13- 7 2,307,463 Lum Jan. 5', 194.3 2,312,566 Lum Mar.j2', 1943i 2,327,782 Golf Aug. 24, 1943: 2,571,649 Arthur Oct. 16,1951. 

